loop devices
Table of Content
loop devices#
A loop device can take file and create pseudo block device
using losetup command we can create and manage loop devices.
create loop device#
create file
# Create 50M file
dd if=/dev/zero of=blockfile bs=1M count=50
create loop device
sudo losetup /dev/loop100 blockfile
Create device partition like any other block device
sudo parted -s /dev/loop100 mklabel msdos
sudo parted -s /dev/loop100 mkpart primary 1MiB 100%
sudo mkfs.ext4 /dev/loop100p1
# mount
sudo mount /dev/loop100p1 /mnt/loop
# umount
umount /mnt/loop
mount block file#
sfdisk -d blockfile
#
label: dos
label-id: 0x7f02b152
device: blockfile
unit: sectors
sector-size: 512
blockfile1 : start= 2048, size= 100352, type=83
echo $((2048 * 512)) $((100352 * 512))
#
1048576 51380224
mount loop devicesudo mount -o loop,offset=1048576,sizelimit=51380224 ~/blockfile ~/mnt
#
sudo mount -o loop,offset=1048576,sizelimit=51380224 ~/blockfile ~/mnt